As far as I know it's not legal to sell anything you don't own the copyright to. For example, if you made super mario stars and sold them you can be taken to court for selling something that's not yours, even though you might have came up with the pattern yourself.
I knew a lady who sold Thomas the Tank Engine fabric by the yard on etsy and was sued by the company.
As for if people would be interested, yes I would think they would be. However, personally, I would not risk the potential law suit.